Checking cracks, which are the majority of cracks seen in beams, often have a starting and stopping place. They happen when the wood dries out. The interior area of the wood is slower to dry than the exterior area of the beam or post, resulting in a slight difference in moisture. This moisture difference creates shrinkage and stress within the beam or post and cracking results. It’s a natural process and is generally not a major concern unless it goes all the way through the beam.
Splitting often starts at notches in a beam, or at the end or edge areas. Splitting can be of a more serious nature then checking. If the beam is splitting and sagging, bowing or bending, then consulting a qualified contractor or engineer would be wise.
Who to consult? Framing contractor.
A significant amount of wood beams and timber cracks over time. When the cracks are of a concern, then consulting with a framing contractor or in rare instances a engineer will provide additional information as to whether it is normal or if repair work would be wise.